The invention relates to improvements in instruments which are utilized to map, ablate, illuminate and/or image the surfaces bounding the cavities or passages in body organs, such as human or other animal hearts. More particularly, the invention relates to improvements in instruments of the type known as endoscopes. An endoscope normally comprises a catheter for a set of optical conductors (e.g., glass fibers) including a first group or array of conductors which serve to direct radiation (e.g., one or more light beams) against selected portions of the surfaces bounding a chamber or passage in a body organ, and a second group or array of conductors which serve to transmit one or more images of the illuminated portions of such surfaces.
Heretofore known endoscopes which employ conductors for the transmission of radiation into and for the transmission of images from internal chambers or passages of body organs exhibit a number of drawbacks. Problems which arise when utilizing conventional endoscopes are particularly acute when the conductors are to illuminate and to transmit images of selected portions of surfaces bounding chambers in a heart or passages in conduits for body fluid (e.g., in a large conduit such as an aorta). The ability of a standard endoscope to properly illuminate and/or image selected portions of surfaces in chambers or passages of various body organs is unduly affected by the body fluid (such as blood) which flows in or through an internal chamber (e.g., a chamber of a heart), a vein or an aorta. The body fluid affects the quality (such as the brightness and sharpness) of the images.
Attempts to overcome the drawbacks of heretofore known endoscopes include the utilization of dissolved salt which is injected into the chamber or passage to be imaged, or the utilization of balloons which are to be inflated so as to expel the body fluid or fluids from that portion of an internal chamber or passage which is to be imaged with a conventional endoscope. Such proposals cannot be resorted to in connection with the imaging of a surface bounding a chamber in a human or other animal heart because the injected saline solution and/or the introduced and inflated balloon would interfere with or would actually interrupt the flow of blood through the heart. Moreover, it would be necessary to utilize an extremely large balloon to expel blood from a chamber in a human or other animal heart which, in turn, would create serious problems in connection with the introduction of a large balloon into or its extraction from a chamber in a heart. In addition, a patient would be likely to die in the course of such inspection of her, his or its heart because the heart would cease to pulsate and to circulate blood in the course of an imaging operation. In addition, the radiation issuing from certain optical conductors in a standard endoscope is likely to flicker which also affects the quality of the images. For the foregoing reasons, heretofore known endoscopes are not suitable for utilization in connection with the irradiation and imaging of surfaces in several chambers or passages of body organs or, if used, are incapable of furnishing satisfactory images or are likely to affect the condition of the patient.